1 U.S. Army Corps of Engineers, Water Resources Support Center, Waterborne Transportation Lines of the United States: Calendar Year 1999 (Fort Belvoir, VA: 2000), also available at http://www.wrsc.usace.army.mil/ndc/veslchar.htm, as of April 2001.
2 U.S. Army Corps of Engineers, Water Resources Support Center, Waterborne Commerce of the United States 1999 (Fort Belvoir, VA: 2001). Domestic ton-miles include commerce among the 50 states, Puerto Rico, the Virgin Islands, Guam, American Samoa, Wake Island, and the U.S. Trust Territories. Domestic total does not include cargo carried on general ferries, coal and petroleum products loaded from shore facilities directly into bunkers of vessels for fuel, transport of less than 100 tons of government materials on government-owned equipment in support of U.S. Army Corps of Engineers projects. Fish are also excluded from internal (inland) domestic traffic.
3 U.S. Department of Transportation, U.S. Coast Guard, Boating Statistics-1998 (Washington, DC: 2000).
4 U.S. Army Corps of Engineers, Navigation Data Center, Geographic Distribution of U.S. Waterway Facilities, available at http://www.wrsc.usace.army.mil/ndc/fcgeodis.htm, as of January 2001.